A SYNOPSIS OF THE APHIDIDAE 101 



121. Aphis euonomi Fabr. 



Figures 182, 187, 190, 205 to 207, 236, 237 



Fabricius, Syst. Ent., p. 736, 1794 (orig. desc.). 



Davidson, Jour. Econ. Ent., vol. 2, p. 302, 1909. A. rumicis Linn, (list, in 



part?). 

 Essig, Mon. Bull. Cal. Comm. Hort., vol. 4, p. 446, 1915. A. rumicis Linn. 



(list). 



Becords Althaea rosea, Berkeley, June, 1915; Hisbiscus moscheutos, Berkeley, 

 July, 1915 : Maytenus boaria, Berkeley, July, 1915 ; Mesembryanthemum equilat- 

 erale, Stanford University, June, 1915; Silybum marianum, Stanford University, 

 July, 1915: Urtica holoserica, Menlo Park, San Mateo County, January, 1915: 

 Calendula officinale, Orange, February, 1917: Antliemis sp., Pasadena, April, 1917: 

 Papaver sp., El Cajon, San Diego County, May, 1916 (Aphis papaveris Fabr.?) : 

 Vicia fdba, Stanford University (Davidson), Oxnard (Essig, 1915), Montebello, 

 Los Angeles County, December, 1916, Eiverside, January to May 1917 (Aphis 

 fabae Scop.?): Eumex spp., Palo Alto, January, 1912 (Davidson), Stanford 

 University, March, 1912 (Morrison), March, 1915, Ventura County, May, 1917: 

 Pliaseolus spp., Ventura County, May, 1917 (Aphis rumicis Linn.?). 



There has been a great deal of confusion regarding the identity 

 of this species of aphid, and as yet its synonomy is not worked out 

 satisfactorily. The following is offered only provisionally by the 

 author. The common black aphid has usually been considered as 

 Aphis rumicis Linn., Aphis euonomi Fabr. being taken as a synonym, 

 but according to Gillette, Linnaeus' description calls for an aphid 

 ' ' brass} 1 - brown in color, and not black according to the popular opin- 

 ion; and its food plant should be species of Eumex." He considers 

 the common black species to be Aphis euonomi Fabr., as does Mord- 

 wilko in the European form. The author follows these two aphidol- 

 ogists in placing Aphis rumicis Linn, of American authors (and later 

 European authors) as a synonym of Aphis euonomi Fabr. He (i.e., 

 Gillette) writes, "whether or not it is synonymous with rumicis we 

 are not certain, but we very much doubt this being the case." As 

 long ago as 1894, Osborn and Sirrine (Iowa Agr. Sta., Bull. 26, p. 

 904, 1894) proved that the species which wintered in Iowa on 

 Euonymus migrated to Eumex and other plants in the summer. In 

 California the author has been unable to find it at any time upon 

 Euonymus, although this is a very common ornamental plant, especi- 

 ally in the vicinity of Riverside. This may be due, however, to the 

 mild winter climate of southern California, which permits plant lice to 

 live throughout the winter, thus not necessitating the laying of eggs. 

 Concerning the identity of the California species the author believes 

 the form described briefly below to be Aphis euonomi Fabr. The 



